1. Field of the Invention
The present invention relates to an air-intaking and exhausting apparatus in an air cooling system for a PDU (power drive unit) and a down converter and particularly, to an air-intaking and exhausting apparatus in an air cooling system for a PDU (power drive unit) and a down converter for use in a hybrid vehicle.
2. Description of the Related Art
For tackling multiple environmental issues to clean the air source, a variety of hybrid vehicles have been researched and developed. Such a hybrid vehicle is known to have an internal combustion engine and an electric motor which is energized with power sources such as a high-voltage and high-power battery. The battery may be of as a high voltage as 144 volts which is fed to an inverter composed of high-current transistors and capacitors for driving e.g. a three-phase electric motor. The hybrid vehicle also includes a down converter for converting the high voltage to a lower voltage.
The inverter and the down converter draw higher currents and will generate heat thus providing a high temperature. In common, the generated heat is attenuated by the cooling action of an air cooler mounted in the interior of the vehicle. However, as the air cooler is used for the purpose, the effect of cooling down the interior of the vehicle will be offset.
It is thus an object of the present invention to provide an air-intaking and exhausting apparatus in an air cooling system for cooling down a PDU and a down converter at higher efficiency without the help of an air cooler mounted in the interior of a vehicle.
The first feature of the invention lies in that an air-intaking and exhausting apparatus in an air cooling system for a PDU and a down converter comprises an air inlet provided in the bottom of a vehicle to open downwardly, an air cooler for the PDU and the down converter connected by a first tube to the air inlet, and an exhaust outlet provided to open downwardly and connected by a second tube to the air cooler, wherein the first tube and the second tube are placed on a horizontal plane and extended substantially orthogonal to each other.
The second feature of the invention lies in that at least a portion of the air inlet faces against the top of a fuel tank.
The third feature of the invention lies in that the air cooler includes a fan for inputting and outputting the flow of air to cool down the PDU and the down converter, and the fan is adapted for turning the direction of the flow of air substantially 90 degrees.
The fourth feature of the invention lies in that the exhaust outlet is located above a silencer.
According to the first feature, the distance between the air inlet and the exhaust outlet is maximized. Also, the air-intaking and exhausting apparatus in an air-cooling system can be mounted on a vehicle without trading off the design quality of the vehicle. According to the second feature, the air inlet hardly allows any object jumping up from the road surface to enter straightforwardly. According to the third feature, the direction of the flow of air can be turned 90 degrees without using any 90-degree elbow tube. According to the fourth feature, the exhaust outlet can be prevented from being frozen, narrowed, and blocked in the cross section.